[Coco] GIME text modes and font data

[Ciaran Anscomb]

William Astle wrote:
> As far as what mess is doing: it appears to be using the HPRINT font 
> data in the ROM as the bitmap data for the hardware font. I know it is 
> doing that because I had mess use a different ROM (which it complained 
> about but let me proceed) which had various patterns in the various 
> relevant address ranges and those patterns showed up on screen in the 
> text modes instead of proper characters. Given that your assessment 
> agrees with mine (from first principles), I assume mess is cheating 
> since I don't see how the real hardware could be doing what mess is doing.

Checking the MESS source, src/mess/video/coco3.c maintains a separate
area for font data which it could populate with hard coded values, but
instead copies data into it from the ROM.  It doesn't simulate decoding
the ROM for looking up font data dynamically.

The implication to me is they know they should be populating that, but as
you say, decided to cheat seeing as the data they wanted was *right there*
(so long as you don't run with another ROM).

..ciaran